Water feed device for humidification and air conditioning apparatus incorporating the same

ABSTRACT

There is provided a water feed device for humidification, comprising: an outflow reservoir that is disposed above a humidifier for feeding water into the humidifier by way of a permeation and that is provided with an overflow dam for maintaining a level of the water in the outflow reservoir substantially constant; an inflow reservoir that is disposed upwards of the outflow reservoir and that is provided with a flow inlet; a partition plate that is disposed between the inflow reservoir and the outflow reservoir; and a plurality of drip feed members which are provided in the partition plate for allowing the water in the inflow reservoir to drop by gravity in a form of droplets into the outflow reservoir. There is also provided an air conditioning apparatus having a dehumidifier, a heater, a humidifier and an air blower successively arranged within an air duct connect to an area to be air conditioned; downwards of respective portions of the cooling dehumidifier unit and the humidifier unit in the air duct there are provided a pair of water proof trays, respectively, which are communicated via respective hoses with the cooling dehumidifier unit and the humidifier unit, respectively, and which are provided with a drainage means that is opening to an outside of the housing; and downwards of the water proof trays and downwards of the air duct there is provided a further water proof tray having a drainage means that is opening to an outside of the housing.

TECHNICAL FIELD

The present invention relates to a water feed device for humidificationand an air conditioning apparatus incorporating the same. Here, thewater feed device for humidification may be designed for use, forexample, in a bid-cultivating chamber, a clean room (box), a constanttemperature and isohumid box for temperature and humidity control, anair conditioning unit for ultra high precision cutting, a semiconductorwafer manufacturing system and so forth. The water feed device forhumidification is used with a humidifier unit for effecting ahumidification while vaporizing pure water or ultra pure water and isadapted to feed into the humidifier unit such pure water serving as thehumidifying water. The air conditioning apparatus here may be associatedwith a spin coating system that is designed to coat a regist upon asurface of a semiconductor while rotating the same or to apply a coatingmaterial upon a substrate of an optical disk, and which is able to feeda constant temperature and isohumid air stream into any of a variety ofoperating stations that are included in such systems.

BACKGROUND ART

In case where it is desirable to feed a given amount of water into areservoir and so forth, it has been customary to use a pump.

In case where water is fed through a pump, there is no difficulty incontrolling the rate of flow of the water. This is not the case,however, where the water is pure water or ultra pure water. Then, a pumpis not suitable for use in feeding the water.

This is attributed to the fact that pure water unlike normal water doesnot contain an impurity which serves to provide a lubricating functionfor a sliding surface contained in a pump and so forth. Thus, if purewater is fed through a unit, such as a customary pump, which involves amechanical friction, there has been encountered the problem that thepump or the like unit is low in its durability and does cause the purewater to be contaminated due to a wear of a component thereof. Shouldthe pure water be ever fed through the pump or the like, a prohibitivelylarge feed equipment would be required, and its system and operationwould be prohibitively costly.

Besides, in this conjunction, while a tube pump is non-contaminative topure water, it must be taken into account that the same is poor in itsdurability and in addition is inconvenient in that a pulsation takesplace unavoidably.

Furthermore, in case where a unit for feeding water through a pump isused with a humidifier unit in which a heating wire made up from a metalor the like is brought into direct contact with water, the problem isbrought about that an electrical leakage may sometimes take placeexternally via the pure water. Thus, pure water (with its resistancevalue of 18 ohm) is by no means an insulator and, if carbon dioxide inthe air is absorbed therein, it will have its resistance value furtherreduced to one tenth. Hence, the problem of an electrical leakage tendsalways to be brought about.

An air conditioning apparatus of the conventional design has beenconstructed as shown, for example, in Japanese Unexamined PatentPublication No. Hei 02-1113. Thus, it typically comprises a coolingdehumidifier unit for cooling an intake air flow to dehumidify thecooled air flow, a heating unit for heating to a predeterminedtemperature the air flow that has been dehumidified by the coolingdehumidifier unit, a humidifier unit for humidifying the resulting airflow to a predetermined humidity and an air blower unit for feeding thehumidified air flow.

And, in the conventional air conditioning apparatus, the air blowerunit, the cooling dehumidifier unit that comprises a heat exchanger fora cooling purpose, the heating unit that comprises a heat exchangerdesigned to adjust the air temperature, and the humidifier unit aresuccessively arranged in a vertical direction within a cylindricalhousing so that a vertical laminar flow of which the temperature and thehumidity are controlled may be fed to an area to be air conditioned,such as a spin coating system as mentioned above, that is positioneddownwards of these components.

In an conventional air conditioning apparatus as mentioned above,however, it must be noted that the water which is removed from the airand condensed at the cooling dehumidifier unit has no way but to beallowed to drop downwards and, if this water happens to adhere onto atemperature and humidity sensor which is provided in the heating unit orthe housing, it follows that an accuracy at which the temperature andthe humidity are controlled could significantly be lowered. Also, if theabove mentioned water happens to get mixed with the conditioned air flowto adhere onto a filter that is provided at an outlet of the housing,the problem has arisen that the filter may be clogged, thussignificantly lowering the rate of the air flow being fed.

It is a first object of the present invention to provide a water feeddevice for humidification, which eliminates a need for a mechanicalwater feed unit, is capable of feeding a given quantity of pure waterinto an evaporation zone in an inexpensive arrangement, and may notgenerate an accident due to the electrical leakage.

Also, it is a second object of the present invention to provide an airconditioning apparatus whereby if water droplets happen to fall bygravity from any of a variety of the components of an air conditioningsystem including the cooling dehumidifier, they could not adhere ontothe heating unit or the temperature and humidity sensing means which areprovided in the housing and could not be introduced into the conditionedair flow at the outlet side to produce a clogging of the filter or toinduce any other adverse effect; there could be no influence from themoisture condensed water at all; and an increased precision at which atemperature and a humidity are controllable is assured.

SUMMARY OF THE INVENTION

In order to attain the first object mentioned above, a water feed devicefor humidification according to the present invention comprises: anoutflow reservoir that is disposed above a humidifier for feeding waterinto the said humidifier by way of a permeation and that is providedwith an overflow dam for maintaining a level of the water in the saidoutflow reservoir substantially constant; an inflow reservoir that isdisposed upwards of the said outflow reservoir and that is provided witha flow inlet; a partition plate that is disposed between the said inflowreservoir and the said outflow reservoir; and a plurality of drip feedmembers which are provided in the said partition plate for allowing thewater in the said inflow reservoir to drop by gravity in a form ofdroplets into the said outflow reservoir. According to the constructionmentioned above, it follows that the water from the said inflowreservoir is allowed to drop in the form of the droplets into the saidoutflow reservoir whereas an excessively fed portion of the water isallowed to overflow the said overflow dam. Accordingly, the water in thesaid outflow reservoir is held in a given quantity and in asubstantially static state. It follows, therefore, that the rate of feedof the water into the humidifier disposed downwards of the said outflowreservoir can be substantially constant. Thus, a need for a mechanicalwater feed unit such as a pump is eliminated and it is possible to feeda given amount of pure water into a vaporization zone of a humidifier inan inexpensive arrangement. In the humidifier, therefore, a highprecision humidity can be maintained substantially constant.

Also, in addition to the construction mentioned above, it is preferredthat the said inflow reservoir and the said outflow reservoir be eachmade up from an insulating material; and that said inflow reservoir andsaid outflow reservoir have each an inner surface that has been treatedso as to be hydrophobic.

According to this construction, an electrical leakage that may otherwisebe transmitted from the said outflow reservoir to the said inflowreservoir via the water can be eliminated owing to the fact that thefeed of the water into the said outflow reservoir is carried out in theform of the droplets and no continuous water film is formed between thesaid inflow reservoir and the said outflow reservoir. Hence, it can bemade unnecessary to utilize an expensive insulating transformer and soforth.

It is also desirable that the said inflow reservoir be provided thereinwith a float switch for detecting a level of the water in the saidinflow reservoir whereas the said flow inlet be provided thereat with anon/off valve, the said on/off valve being controllable in response to asignal from the said float switch for controlling a rate of inflow ofthe water from the said flow inlet into the said inflow reservoir.

In order to attain the second object mentioned above, an airconditioning apparatus according to the present invention ischaracterized in that a cooling dehumidifier unit, a heater unit, ahumidifier unit and an air blower unit are successively arranged withinan air duct which is provided in a horizontal direction in a housing;that the said air duct is provided with an outlet side that is connectedto an outlet duct which is opening towards an area to be airconditioned; that downwards of respective portions of the said coolingdehumidifier unit and the said humidifier unit in the said air ductthere are provided a pair of water proof trays, respectively, which arecommunicated via respective hoses with the said cooling dehumidifierunit and the said humidifier unit, respectively, and which are providedwith a drainage means that is opening to an outside of the said housing;and that downwards of the said water proof trays and downwards of thesaid air duct there is provided a further water proof tray having adrainage means that is opening to an outside of the said housing.

According to the construction mentioned above, it can been seen that ifwater droplets happen to fall by gravity from any of a variety of thecomponents of an air conditioning system including the coolingdehumidifier unit, they will be accepted by one or both of the saidtrays and will thereafter be discharged out of the housing. Hence, itfollows that such water droplets may not adhere onto the temperature andhumidity sensing means provided in the heater or the housing and may notbe introduced into the conditioned air flow at the outlet side toproduce a clogging of the filter or to induce any other adverse effect;there could thus be no influence from the moisture condensed water atall; and an increased precision at which a temperature and a humidityare controllable is assured.

In connection with the above, it may be noted that it is desirable thatthe said outlet duct be directed downwards and have a forward endthereof which is provided with a filter. It is also desirable that therebe provided a temperature and humidity sensing means in the said outletduct; and that each of the above mentioned units be adapted to becontrolled by the said power supply controller in response to a value ofdetection of the said temperature and humidity sensing means.Alternatively, it may be desired that there be provided a temperatureand humidity sensing means downwards of and in the proximity of the saidfilter; and that each of the units mentioned above be adapted to becontrolled by the said power supply controller in response to a value ofdetection of the said temperature and humidity sensing means.

Furthermore, an air conditioning apparatus according to the inventionmay be characterized in that a cooling dehumidifier unit, a heatingunit, a humidifier unit and an air blower unit are successively arrangedwithin an air duct which is provided in a housing in a horizontaldirection; that the said air duct is provided with an outlet side thatis connected to an outlet duct which is opening towards an area to beair conditioned; that downwards of respective portions of the saidcooling dehumidifier unit and the said humidifier unit in the said airduct there are provided a pair of water proof trays, respectively, whichare communicated via respective hoses with the said cooling dehumidifierunit and the said humidifier unit, respectively, and which arc providedwith a drainage means that is opening to an outside of the said housing;that downwards of the said water proof trays and downwards of the saidair duct there is provided a further water proof tray having a drainagemeans that is opening to an outside of the said housing; and

the said apparatus is associated with a water feed device for the saidhumidifier unit, which device comprises: an outflow reservoir that isdisposed above the said humidifier unit for feeding water into the saidhumidifier unit by way of a permeation and that is provided with anoverflow dam for maintaining a level of the water in the said outflowreservoir substantially constant; an inflow reservoir that is disposedupwards of the said outflow reservoir and that is provided with a flowinlet; a partition plate that is disposed between the said inflowreservoir and the said outflow reservoir; and a plurality of drip feedmembers which are provided in the said partition plate for allowing thewater in the said inflow reservoir to drop by gravity in a form ofdroplets into the said outflow reservoir.

BRIEF EXPLANATION OF THE DRAWINGS

The present invention will better be understood from the followingdetailed description and the drawings attached hereto showing certainillustrative embodiments of the present invention. In this connection,it should be noted that such embodiments as illustrated in theaccompanying drawings are intended in no way to limit the presentinvention, but to facilitate an explanation and understanding thereof.

In the accompanying drawings:

FIG. 1 is a cross sectional view illustrating a certain embodiment ofthe water feed device for humidification according to the presentinvention.

FIG. 2 is a cross sectional view illustrating an alternative embodimentof a drip feed member in the above mentioned embodiment of the presentinvention;

FIG. 3 is a graph diagrammatically illustrating the relationship of thevolume rate of drip feed of the water with respect to the level of thewater in the inflow reservoir for different types of drip feed membersin the above mentioned embodiment of the present invention;

FIG. 4 is a graph illustrating the relationship between the amount ofheating electric power in the heating unit and the mass rate ofevaporation of the water;

FIG. 5 is a cross sectional view diagrammatically illustrating anexample of the use of an air conditioning apparatus according to thepresent invention;

FIG. 6 is a cross sectional view diagrammatically illustrating a firstembodiment of the air conditioning apparatus according to the presentinvention; and

FIG. 7 is a cross sectional view diagrammatically illustrating a secondembodiment of the air conditioning apparatus according to the presentinvention.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, suitable embodiments of the present invention with respectto the water feed device for humidification and the air conditioningapparatus incorporating the same will be set forth with reference to theaccompanying drawings.

FIG. 1 shows a first embodiment of the water feed device forhumidification according to the present invention.

As shown in the Figure, a water supply reservoir assembly, which isdesignated by reference numeral 1, is constructed so as to beelectrically insulating and is divided into an upper and a lower part bya partition plate 2. Located at the upper part there is an inflowreservoir 1a, and lying at the lower part there is a outflow ordischarge reservoir 1b. And, the inflow reservoir 1a is formed in a sidewall thereof with a flow inlet 3 and is provided interiorly with a floatswitch 4 that is pendent from the top wall thereof for detecting a levelof the water therein. In this connection, it should be noted that theflow inlet 3 is provided thereat with an on/off valve 3a which isadapted to be controlled in response to a signal from the float switch 4for controlling the inflow rate of the water through the flow inlet 3.On the other hand, the outflow reservoir 1b is provided with an overflowdam 5 for maintaining a level of the water in the outflow reservoir 1bsubstantially constant and is formed in a side wall thereof with a flowoutlet 6 for draining the water overflowing the overflow dam 5 into theoutside thereof.

The above mentioned partition plate 2 is formed with a plurality ofcommunicating ports 7 for communicating the upper reservoir 1a with thelower reservoir 1b. Each of the communicating ports 7 is fitted with adrip feed nozzle 8 that is opening expandingly downwards. Each of thedrip feed nozzles 8 is made up from an insulating material and has itsinner surface that has been treated so as to be of a hydrophilic nature.And, its bore diameter is dimensioned to be not greater than 2 mm and isso configured that the water passing therethrough may drop by gravity inthe form of droplets. It should also be noted that both of the abovementioned upper and lower reservoirs 1a and 1b each have its innersurface that has been so treated as to be hydrophobic.

Downwards of the outflow or discharge reservoir 1b there is located ahumidifier 9. In this humidifier 9, there are spanned a plurality ofhollow textile thread bodies 13, which are each water permeable, betweena bottom plate 10 of the outflow reservoir 1b and an upper plate 12 of alower reservoir unit 11, with each hollow textile thread body 13communicating between the outflow reservoir 1b and the lower reservoirunit 11. And, each of these hollow textile thread bodies 13 is woundthroughout its whole length with a metallic wire 14 and each of themetallic wires 14 is connected via a pair of electrodes 15a and 15b to apower supply 16. Intermediate between the outflow reservoir 1b and thelower reservoir unit 11 there are formed air passageways 17 such thateach of the hollow textile thread bodies 13 may be exposed with a windthat is passing therethrough.

In the construction mentioned above, the pure water that is introducedthrough the flow inlet 3 will naturally flow down to be charged in theinflow reservoir 1a. The inflow flow rate of the water introduced fromthe flow inlet 3 will be controlled by controlling the on/off valve 3ain response to a signal from the float switch 4 so that the level of thepure water in the inflow reservoir 1a may be maintained within apredetermined range at all the times. The pure water within the inflowreservoir 1a will be allowed to drop by gravity through the drip feednozzles 8 formed in the partition plate 2 into the outflow reservoir 1b.And, the water level within this outflow reservoir 1b will be maintainedsubstantially constant by means of the overflow dam 5, and the purewater overflowing the overflow dam 5 will be drained through theeffluent outlet 6.

While the pure water within the outflow or discharge reservoir 1b isbeing allowed to flow down little by little through the hollow textilethread bodies 13, it will be permeated onto their individual surfaces.At the same time, the permeated pure water will be vaporized by means ofthe metallic wires 14 which generates heat with an electric currentpassed therethrough. It follows, therefore, that a wind traversing thepassageways 17 will be humidified with a vapor of this pure water.

In the operation mentioned above, owing to the fact that feeding thepure water from the inflow reservoir 1a into the outflow reservoir 1b iscarried out by its dropping through the drip feed nozzles 8, the purewater within the outflow or discharge reservoir 1b will be held in anextremely static state.

According to this embodiment of the present invention, it can thus beseen that the water from the inflow reservoir 1a is allowed to drop inthe form of the droplets into the outflow reservoir 1b whereas anexcessively fed portion of the water is allowed to overflow the overflowdam 5. Accordingly, the water in the outflow reservoir 1b is held in agiven quantity and in a substantially static state. It follows,therefore, that the rate of feed of the water into the humidifier 9disposed downwards of the outflow reservoir 1b can be substantiallyconstant. Thus, a need for a mechanical water feed unit such as a pumpis eliminated and it is possible to feed a given amount of pure waterinto a vaporization zone of the humidifier 9 in an inexpensivearrangement. In the humidifier 9, therefore, a high precision humiditycan be maintained substantially constant.

Also, owing to the fact that the feed of water into the outflow ordischarge reservoir 1b is by way of a dripping as mentioned above, itwill be seen that if the pure water within the outflow reservoir 1b iselevated in its electrical potential due to an electrical leakage fromthe heating portion of the humidifier 9, there will be no electricalleakage whatsoever from the dripping portion up to the inflow reservoir1a. As a consequence, there will be no electrical leakage whatsoeveroutwards via the pure water that is introduced through the flow inlet 3of the inflow reservoir 1a.

It can also be seen that since both of the inflow reservoir 1a and theoutflow reservoir 1b have each its inner surface rendered hydrophobic,the water will not adhere onto either inner surface of both of the tworeservoirs 1a and 1b so that there may develop no continuous film of thewater between the two reservoirs 1a and 1b, thus preventing whatsoeverelectrical leakage that may otherwise be produced through theirrespective inner surfaces.

The drip feed nozzles 8 in the above mentioned construction may be madeup from a rigid material, such as a high polymer, for example, 6-nylonor 66-nylon, or a polypropylene, whose surface has been treated so as tobe hydrophilic. As shown in FIG. 2, however, they may alternatively beeither hollow. fibrous threads 18 or non-hollow fibrous members. In anycase, a note is taken here of the fact that they have been treated so asto be hydrophilic.

FIG. 3 is a graph showing the relationships of the volume rates of feedof the water with respect to the level of the water in the inflowreservoir 1a in case where the drip feed members are each constituted bythe dripping nozzle 8 having an inner diameter of 2 mm or the hollowfibrous threads 18 having an outer diameter of 1.9 mm and an innerdiameter of 1.0 mm. It has been found that the respective volume ratesof water feed are varied in accordance with the level of the water inthe inflow reservoir 1a.

FIG. 4 is a graph showing the relationship of the mass rate ofevaporation of the water with respect to the amount of the heatingelectric power for the humidifier 9. It has been found that for a givenamount of electric power, the mass rate of evaporation of the water islargely varied as the volume rate of feed of the water into thehumidifier 9 is varied.

While in the above mentioned embodiment of the present invention anexample has been shown in which the humidifier 9 utilizing the hollowtextile threads is disposed at a downward side of the outflow reservoir1b, it should be noted that an arrangement may be employed in whichthere is provided in the bottom plate of the outflow reservoir 1b asingle flow outlet through which a given amount of the water is fed intoa boiler type humidifier.

An explanation will now be given with respect to an air conditioningapparatus which incorporates a water feed device for humidification asmentioned hereinbefore. FIG. 5 shows an example of the use of an airconditioning apparatus according to the present invention. As shown inthe Figure, there are arranged a clean room 21 into which the air isintroduced via a filter 21a, a spin coating unit 22 that is disposed onthe floor of the clean room 21, and a built-in air conditioningapparatus 23 that is disposed upon the spin coating unit 22 and that isconstructed in accordance with the present invention.

The air conditioning apparatus 23 is constructed as shown in FIG. 6 andis provided with a cooling dehumidifier unit 25, a heating unit 26, ahumidifier unit 27 and an air blower unit 28 of centrifugal fan type,which are arranged in series in an air duct 29 that is disposed in ahorizontal direction within a housing 24. And, the cooling dehumidifierunit 25 is opposed to an inlet side of the air duct 29 that is providedwith a preliminary filter 30, and the air blower unit 28 has an outletside that is connected to an outlet duct 31 which is tapered and isopening expandingly downwards. This outlet duct 31 is opening to thelower surface of the housing 24 via a high performance filter 32, with aportion of the opening being opposed to the area to be air conditionedin the spin coating unit 22. In this connection, it should be noted thatthere is connected to the humidifier unit 27, a water feed device forhumidification as mentioned above.

A cooling water generator 33 is connected via a pump 34 to the coolingdehumidifier 25. This cooling water generator 33 and the heater unit 25,the humidifier unit 27 and the air blower unit 28 mentioned above areconnected to a power supply controller 35, which is designed to controleach of the above mentioned units in response to a value of detection ofa temperature and humidity sensing means 36 that is disposed within theabove mentioned outlet duct 31 so that the temperature, humidity andflow rate of the air being fed may be held at respective predeterminedvalues.

Downwards of the cooling dehumidifier unit 25 and the humidifier unit 27of the air duct 29 mentioned above there are provided, respectively, apair of water proof trays 37 and 38, which are connected via a pair ofhoses 37a and 38b to the cooling dehumidifier unit 25 and the humidifierunit 27, respectively. Also, a lower portion of the housing 24, exceptfor a region of the outlet duct 31, is entirely sealed in a water tightconfiguration, and is provided therein with a further water proof tray39, which is in turn provided with a drainage outlet 40. To thisdrainage outlet 40 there are connected the above mentioned trays 37 and38 as well. Also, the said further tray 39 has the above mentionedcooling water generator 33 mounted thereon.

According to the construction mentioned above, the air in the clean room21 will be sucked from the inlet of the air duct 29 via the preliminaryfilter 30 by driving the air blower unit 28. In the meantime, a flow ofthis air, while passing through the air duct 29, will be cooled to bedehumidified at the cooling dehumidifier unit 25, will then be heated bythe heater unit 26, will subsequently be humidified by the humidifierunit 27 and, thus upon having been given a predetermined temperature andhumidity, will finally be fed from the outlet duct 31 via the highperformance filter 32 towards a side of the spin coating unit 22. Atthis instant, the temperature and the humidity of the air being fed willbe detected by the temperature and humidity sensing means 36, and thepower supply controller 35 will act to control each of the abovementioned unit in response to a value of the detection made thereby.

In the operation mentioned above, at the side of the coolingdehumidifier unit 25, the moisture in the air that has passedtherethrough will be condensed, with the condensed moisture fallingthrough an endothermic member such as a fin, then being received by thewater proof tray 37 that is disposed downwards thereof and finally beingdischarged through the drainage outlet 40 into the outside of thehousing 24.

Also, at the side of the humidifier unit 27, in case the water that hasbeen fed there is leaked, any such a leakage will be received in thewater proof tray 38 which is provided downwards thereof and will then bedischarged through the drainage outlet 40 into the outside of thehousing 24.

Furthermore, In case an amount of the water is leaked from the waterproof tray 37 or 38 mentioned above or from any conduit reaching there,any such leakage will be received in the further water proof tray 39which is provided at the low portion of the housing 24 and will then bedischarged through the drainage outlet 40 into the outside of thehousing 24.

According to the above mentioned construction, it can thus be seen thatif water droplets happen to fall by gravity from any of a variety of thecomponents of the air conditioning system including the coolingdehumidifier unit 25, owing to the fact this water is received by thetrays 37, 38 or 39 and then discharged out of the housing 24 thesedroplets may not adhere onto the heating unit 26 or the temperature andhumidity sensing means 36 provided in the housing 24 and may not beintroduced into the conditioned air flow at the outlet side to produce aclogging of the filter 32 or to induce any other adverse effect; therecould be no influence from the moisture condensed water at all; and anincreased precision at which a temperature and a humidity arecontrollable is assured.

Finally it should be pointed out that the temperature and humiditysensing means 36 in an alternative embodiment in contradiction to theembodiment set forth above may be disposed downwards of and in thevicinity of the filter 32 as shown in FIG. 7.

While the present invention has hereinbefore been described with respectto certain illustrative embodiments thereof, it will readily beappreciated by a person skilled in the art to be obvious that manyalterations thereof, omissions therefrom and additions thereto can bemade without departing from the essence and the scope of the presentinvention. Accordingly, it should be understood that the presentinvention is not limited to the specific embodiments thereof set outabove, but includes all possible embodiments thereof that can be madewithin the scope with respect to the features specifically set forth inthe appended claims and encompasses all equivalents thereof.

What is claimed is:
 1. A water feed device for humidification,comprising:an outflow reservoir that is disposed above a humidifier forfeeding water into said humidifier by way of a permeation and that isprovided with an overflow dam for maintaining a level of the water insaid outflow reservoir substantially constant; an inflow reservoir thatis disposed upwards of said outflow reservoir and that is provided witha flow inlet; a partition plate that is disposed between said inflowreservoir and said outflow reservoir; and a plurality of drip feedmembers which are provided in said partition plate for allowing thewater in said inflow reservoir to drop by gravity in a form of dropletsinto said outflow reservoir.
 2. A water feed device for humidificationas set forth in claim 1, characterized in that said inflow reservoir andsaid outflow reservoir are each made up from an insulating material; andthat said inflow reservoir and said outflow reservoir have each an innersurface that has been treated so as to be hydrophobic.
 3. A water feeddevice for humidification as set forth in claim 1 or claim 2,characterized in that said inflow reservoir is provided therein with afloat switch for detecting a level of the water in said inflow reservoirwhereas said flow inlet is provided thereat with an on/off valve saidon/off valve being controllable in response to a signal from said floatswitch for controlling a rate of inflow of the water from said flowinlet into said inflow reservoir.